Shocked

This woman is very masochistic, which means that she derives pleasure from being hurt. Another woman would have already gotten the hint that you have no interest in her when her calls and emails aren't being returned. This woman thrives on being hurt and humiliated, so she doesn't take the hint and keeps pursuing you, knowing full well that a rejection is waiting for her.

I know you want to end it cleanly, but this woman isn't going to be that easy to brush off. She hasn't suffered enough yet. All you can do is be clean on your side of the fence. Email her a message saying that you are not interested in pursuing a relationship and that you don't want to receive any more calls or emails.

Don't call, since you might get her in person. Because she looks to be hurt, she will probably pursue you even after you give her a clean and clear communication. Once you have emailed her, ignore any further communications from her. Keep in mind that any response from you will be rewarding her masochistic urge to be hurt and humiliated. Ignoring her and giving her no contact at all will eventually make her leave you alone in search of greener abuse pastures.